Current and recent projects include studies of the pattern and tempo of adaptive divergence in the Hawaiian lobeliads, the largely South American families Bromeliaceae and Rapateaceae, and the North American mariposas (Calochortus) and lilies (Lilium).

I am also coordinating efforts by the Monocot AToL team to derive a fully resolved, strongly supported phylogeny for representatives of all families and subfamilies of the monocots. The monocots – including such groups as grasses, sedges, palms, gingers, bananas, onions, yams, pondweeds, and philodendrons – comprise 65,000 species, 92 families, and 12 orders of flowering plants, occur in almost all habitats on Earth, and provide the basis for the great majority of the human diet. Monocots also account for much of the commerce in cut flowers and horticultural bulbs such as crocuses, irises, hyacinths, tulips, and lilies. They dominate grasslands, seagrass beds, bamboo thickets, many wetlands, and are especially common on extremely infertile soils. Our team – including ten PIs at Cornell, New York Botanical Garden, Penn State, University of British Columbia, University of Georgia, University of Missouri, and University of Wisconsin-Madison – will be sequencing the entire chloroplast and mitochondrial genomes of 600 taxa, as well as the entire transcriptomes of 50 taxa, producing an avalanche of new data to reconstruct the phylogeny of the economically most important group of plants, thus opening the door to a wide range of new comparative studies on monocot morphology, ecology, biogeography, and gene expression.

Rebecca Montgomery and I continue to investigate the ecology and evolution of photosynthetic light adaptations in the Hawaiian lobeliads, using field studies, physiological measurements, and common-garden experiments to re-examine several classic ecological questions in a phylogenetic context and test whether the lobeliads have, in fact, undergone an adaptive radiation. We have shown that different lineages have radiated into different portions of the light gradient on moist substrates in Hawai`i; that the lobeliads show the expected shifts in a variety of photosynthetic parameters and whole-plant light compensation points upon invasion of different light regimes; and that species show adaptive cross-over in photosynthetic response. We are now studying the adaptation of lobeliads to gradients of light x water availability, to address the extent to which adaptations to light supply are actually adaptations to water supply and demand.

Adaptation and speciation on islands are recurring themes of my research, and I am eager to recruit a student interested in directly testing my recent model for the evoluton of woodiness in island plants.